Core form for concrete member



United States Patent OTHER REFERENCES PATENTE!) nfceelgm SHEET l UF 4 a Rond/d l?. Ferry Robert May INVENTORS PATENTED 05u22 |910 SHEEY 2 UF 4 Rona/d R. Ferry Robert f?. May

INVENTORS @5% A Homey:

PMENTEUnfnzemm `352451116 SHEET lt UF 4 I Rona/d Ferry Raberf l?. May

yINI/ENTOKS m' www @Mmm CORE FORM FOR CONCRETE MEMBER This invention relates to the manufacture and assembly of paperboard voids for use in precast concrete members such as hollow beams and other structural concrete members.

The casting of concrete about internal voids constitutes a necessary feature in the manufacture of concrete beams and in particular prestressed concrete beams. The voids are formed by paper board cores. The void-forming core must be capable of withstanding the weight of the wet concrete when poured and also suiciently rigid to resist deformation due to tools employed in the casting of the concrete. Another important consideration in the construction of the paperboard core, is the simplicity with which the core is assembled, the cost of its parts as well as the weight and storage capabilities of the parts.

Thus, an important object of the present invention is to provide for the manufacture and assemblyof paperboard cores from standardize parts which will nevertheless provide a selection of sizes. Other objects of the invention are to reduce the weight and cost of the paperboard core yet maintain the requisite strength as well as to simplify the assembly of the parts.

ln accordance with the present invention, the paperboard core includes an outer tubular shell formed from a plurality of sections instead of a single blank. At least four comer sections are utilized to form the smaller size cores while two additional side sections may be added in order to enlarge the core being assembled. The sections which form the outer shell include abutting flanges that extend inwardly into the shell and are interlocked with inner supports not'only to hold the shell assembled but to also increase the internal strength of the core. At least one end of the shell is closed by an end cap and end supports which space the sides of the shell are assembled between the end cap andthe adjacent inner support panel in order to provide the additional internal strength needed adjacent the closed end of the core.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part herof, wherein like numerals refer to like parts throughout, and in which:

FIG. l is a perspective view of a hollow concrete beam broken away to expose the void forming core about which the concrete is cast;

FIG. 2 is a perspective view showing a portion of an elongated core assembly made in accordance with the present invention;

FIG. 3 is an enlarged partial sectional view taken substan- FIG. 4 is a sectional view taken substantially through a plane indicated by section line 4-4 in FIG. 3;

FIG. 5 is a transverse sectional view taken substantially through a plane indicated by section line 5-5 in FIG. 4;

FIG. 6 is a perspective view showing the disassembled parts which form a paperboard core constructed in accordance with the present invention; and l FIGS. 7, 8 and 9 are perspective views showing the end portions of void forming cores of jdifferent standard sizes constructed in accordance with the principles of the present invention.

Referring now to the drawings in detail, FIG. l illustrates a hollow concrete beam cast'within an outer mold 14. Steel strands 16 are embedded within the concrete l0 as shown in `surrounding relation to the core l2. It will be appreciated, that the core must be dimensioned in accordance with the desired void and must also have the requisite strength to withstand deformation during the pouring of wet concrete when casting the hollow beam. The core l2 as illustrated in FIGS. 1 and 2, extends longitudinally the length of'the beam with which it is associated and is made of a plurality of standard length core assemblies which are interconnected by joint sleeves 18. The end core assembly is provided with an end cap 20 so as to close the otherwise open tubular shell 22 from which the core assembly is made. The core assembly is generally rectangular in cross section in the embodiment shown in FIGS. l and 2. lt will of course be appreciated that other cross-sectional configurations may also be employed. Also, as hereinbefore pointed out all of the parts from which the core is assembled, are made of blanks formed from internally corrugated paperboard. Some of the blanks are also formed with slots and some of the blanks are folded during assembly as will hereafter become apparent.

Referring now to FIG. 6 it will b e observed that each of the core assemblies has associated therewith a plurality of flat, paperboard support panels 24 which are generally square in shape in the illustrated embodiment. Each support panel is peripherally formed by parallel side edges 26 perpendicular to parallel side edges 28, the side edges being interconnected by chamfered comer edges 30. The side edges 26 are provided with centrally located slots 32. On either side of the slots 32, are notches 34 which form drain passages. The side edges 28 on the other hand are provided with two slots 36. The periphery of the support panels conform to the cross-sectional shape of the outer shell 22 and are equally spaced from each other along the longitudinal axis of the outer shell in order to form an internally rigid support for the outer shell. The notches 34, slots 32 and slots 36 are aligned with each other when the support panels are assembled as shown.

The outer shell 22 is assembled from at least four corner sections 38 folded from flat blanks as shown, to form relatively wide side portions 40 and relatively narrow side portions 42 interconnected by corner chamfer portions 44. The side portions 40 and 42 are folded perpendicular to each other and are respectively provided with inwardly extending flanges 46 and 48. The flanges 46 and 48 are provided with a plurality of slots 50 which are longitudinally spaced from each other a distance equal to the spacing between the inner support panels 24. Thus, the slots 50 interit with the slots 32 and 36 of the support panels so that the side portions 40 and 42 may abut -the side edges 26 and 28 of the supportlpanels while the chamfer portions 44 abut the chamfer edges 30.

Also associated with the outer shell 22, are a pair of side sections 52. Each side section is .provided with a pair of parallel flanges 54 formed with slots 56 equal in spacing to the inner support panels 24 so that the flanges 54 may interflt with the slots 36 of the support panels. Thus, the side sections 52 abut the side edges 28 of the support panels when interlocked therewith.

It will be appreciated, that the outer shell formed by the four corner sections 38 and the two side sections 52 will be open at the opposite longitudinal ends. At least one of the open ends may be closed by an end cap 58 having side flaps 60 and comer flaps 62 conforming to the cross-sectional configuration of the outer shell to which the end cap is secured. In order to internally rigidify the outer shell adjacent to the end cap, four end supports 64 are provided which occupy the axial space between the end cap 53 and the adjacent inner support panel 24. Each end support 64 is folded into a channel-shaped configuration having abutting side legs 66. The open end of the outer shell opposite the end cap 58 may be secured to an adjacent core assembly by means of the joint sleeve 18 aforementioned which is a relatively narrow strip of paperboard folded to the cross-sectional configuration of the outer shell overlapping the outer shells of the two adjacent core assemblies.

Referring now to FIGS. 3, 4 and 5, the assembly of the various parts of the core assembly will become apparent. Thus,

the slots 32 and 46 of the inner support panel 24 and the slots 50 and 56 of the outer shell sections. Thus, the inner support panels hold the sections of the outer shell assembled and internally resist collapse of the outer shell. The end supports 64 fit between the inwardly extending flanges 46 and 54 and space the larger sides of the outer shell formed by the wide side portions 40 of the comer sections 38. The end cap 58 is then secured in place closing the open end of the outer shell by means of the flaps 60 and 62 utilizing staples for example. The opposite open end of the outer shell is connected to an adjacent core assembly by means of the joint strip 18 as more clearly seen in FIGS. 3 and 4.

ln order to form a core assembly of smaller cross-sectional area, the side sections 52 of the core assembly 12 hereinbefore described, may be removed and a correspondingly smaller inner support panel 24' utilized as shown in FIG. 7 wherein the flanges 46 extending from the narrow side portions 42 of the corner sections abut each other as do the side flanges 46 extending from the wider side portions 40. End supports 64' of shorter length must also be utilized.

In FIG. 8, a core assembly is shown wherein the comer sections 38' of the outer shell are formed with side portions 40' which are wider than the side portions 40 hereinbefore described in connection with the comer sections 38. Accordingly, a cross-sectionally longer coreA will be formed with correspondingly longer inner support panels 24". Wider end supports 64 must also be utilized in order to occupy the space between the flanges which extend inwardly from the narrow side portions of the comer sections 38'.

ln order to form a core assembly which is generally square in cross section, side sections 52 may be utilized with comer sections 38' as Shown in FIG. 9. Correspondingly square inner support panels 24"' are accordingly utilized and relatively longer end supports 64"' must also be utilized as shown. It will therefore be appreciated, that by stocking corner sections, end supports and inner support panels of different standard sizes, a wise selection of dimensionally different core assemblies will be available in order to meet the requirements of the precast concrete manufacturer.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is Vnot desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.

We claim:

1. A core device made from paperboard blanks and adapted to be positioned within a mass of concrete to form a void in a precast structural member comprising an outer shell having open ends, an end closure closing at least one of said open ends of the outer shell, and a plurality of planar support panels enclosed in spaced relation to each other within said outer shell, said outer shell including at least four separate corner sections and means interlocking said support panels with the separate corner sections holding the same assembled.

2. The combination of claim l wherein said interlocking means includes abutting flanges extending inwardly from the comer sections having slots interlocking the flanges with the su'pport panels in said spaced relationship.

3. The combination of claim 2 wherein each of said corner sections further includes perpendicular side portions interconnected by a chamfer portion, said flanges extending from the side portions being spaced from the chamfer portion.

4. The combination of claim 3 wherein each of` said support panels includes a generally rectangular member having corner chamfer edges engaging the chamfer portions of the corner sections, and side edges having slots receiving the abutting flanges of the comer sections and notches forming drain passages within the outer shell.

5. The combination of' claim 4 including a plurality of end channel supports disposed between the abutting flanges spacing the side portions of the corner sections adjacent the end closure.

6. The combination of cla1m 5 wherein said outer shell further includes at least two side sections having flanges abutting the flanges of the comer sections and interlocked with the support panels.

7. The combination of claim 2 including a plurality of end channel supports disposed between the abutting flanges spacing the corner sections adjacent the end closure.

8. The combination of claim 7 wherein said outer shell further includes at least two side sections having flanges abutting the flanges of the corner sections and interlocked with the support panels.

9. The combination of claim l wherein said outer shell further includes at least two side sections having flanges abutting the flanges of the corner sections and interlocked with the support panels.

10. The combination of claim 1 wherein each of said support panels includes a generally rectangular member having comer chamfer edges engaging the comer sections, and side edges having slots interlocked with the corner sections and notches forming drain passages within the outer shell.

1l. A core device made from paperboard blanks comprising an outer shell formed from a plurality of separate comer sections, each corner section including side portions and flanges extending inwardly from said side portions having spaced slots formed therein, and a plurality of planar support panels enclosed by the outer se shell and interlocked with said flanges in longitudinally spaced relation to each other.

l2. The combination of claim 11 wherein each of said support panels is provided with peripheral edges engaging the comer sections between the flanges and slots formed in the edges interlockingly receiving the flanges, said flanges being provided with fixedly spaced slots intertting with said slots formed in the edges.

13. The combination of claim 12 wherein some of said flanges abut each other. 

